Cobalt is the first element in the ninth column of the periodic table. It is classified as a transition metal. Cobalt atoms have 27 electrons and 27 protons with 32 neutrons in the most abundant isotope.

Characteristics and Properties

Under standard conditions cobalt is a hard, brittle metal with a bluish-white color. It is one of the few elements that is naturally magnetic. It can be easily magnetized and maintains its magnetism at high temperatures.

Cobalt is only somewhat reactive. It reacts slowly with oxygen from the air. It forms many compounds with other elements such as cobalt(II) oxide, cobalt(II) fluoride, and cobalt sulfide.

Where is cobalt found on Earth?

Cobalt is not found as a free element, but is found in minerals in the Earth's crust. Cobalt ores include erythrite, cobaltite, skutterudite, and glaucodot. The majority of cobalt is mined in Africa and is a byproduct of the mining of other metals including nickel, copper, silver, lead, and iron.

How is cobalt used today?

Most of the cobalt that is mined is used in superalloys which are very resistant to corrosion and are stable at high temperatures.

Cobalt is also used as a blue coloring agent in paints, inks, glass, ceramics, and even cosmetics.

Other applications for cobalt include batteries, industrial catalysts, electroplating, and powerful magnets.

How was it discovered?

Cobalt was discovered by Swedish chemist George Brandt in 1735. He isolated the element and proved that it was the source of the color in blue glass which previously was thought to be from bismuth.

Cobalt compounds were used throughout ancient history by civilizations such as Ancient China and Rome to make blue glass and ceramics.

Cobalt is also important for animal life. The body uses it to create certain enzymes. It is also a component of the vitamin B12.

Where did cobalt get its name?

Cobalt gets its name from the German word "kobalt" which means "goblin." Miners gave cobalt ore this name as they were superstitious about mining the ore.

Isotopes

Cobalt only has one stable isotope that is found in nature: cobalt-59.

Oxidation States

Cobalt exists with oxidations states ranging from -3 to +4. The most common oxidation states are +2 and +3.

Interesting Facts about Cobalt

Cobalt was the first metal to be discovered since prehistoric times and the first metal with a recorded discoverer.

Cobalt-60 is used to create gamma rays which are used to treat cancer and to sterilize medical supplies.

Too much or too little cobalt in the body can cause health issues.

Small amounts of cobalt are sometimes used in fertilizers.

Most of the cobalt used in the United States is imported from other countries.